Former Labour councillor Bill Cherrington will represent Nigel Farage's party on Sandwell Council, and is due to defend his Princes End seat next May.
Mr Cherrington, who was first elected in 2012, has vowed to take the fight to his former colleagues in Sandwell's Labour group.
"I decided to move to the Brexit Party as I feel that that Labour group in Sandwell is clamping down on free speech and stifling democracy," he said.
"The response from my family, friends, and the many voters that I have spoken to in the Princes End ward about this move, has been overwhelming.
"I have already received countless offers of help and support."
As a Labour councillor, Mr Cherrington retained his seat in the 2015 local elections.
He was kicked out of the party earlier this year amid political turmoil in Sandwell, having been accused alongside two other councillors of campaigning for opposition candidates.
Mr Cherrington had sat as an independent since July after a brief spell in the United Sandwell Group, which he formed alongside Councillor Caroline White to challenge allegations of corruption in the borough's Labour group.
Pete Durnell, West Midlands organiser for the Brexit Party, said: “Bill’s experience of being a councillor since 2012 will prove incredibly useful over the coming months, not just in the local elections, but in the general election.
"His knowledge of the West Bromwich West constituency will be particularly invaluable to our prospective parliamentary candidate for West Bromwich West, Franco D’Aulerio
"Our large and rapidly growing army of local supporters will be fully behind Councillor Cherrington, and will work tirelessly to ensure that he is re-elected in May.
"I know that Bill very much wants to be able to continue to assist Princes End residents as one of their councillors for another four year term, and we will do everything we can to ensure that he has the opportunity to do so."
The Brexit Party was founded earlier this year in opposition to the UK Parliament's failure to deliver Brexit.
It was the biggest party in the European elections, returning 29 MEPs including three in the West Midlands, but did not stand candidates in last May's local elections.
It now has representation on Rotherham Council, where 12 councillors joined from Ukip, and took over its first authority in Hartlepool, after 10 independents joined.